Tarkeeb, in the English language, could be best translated as "Sentence Parsing"; though, to explain the concept of it to an English speaker may prove difficult, as neither does English nor - to the best of our knowledge - any other language have such a component as "Tarkeeb". That is, the critical analysis of speech and text; breaking it down sentence by sentence, and analysing those sentences, analysing each and every word in the sentence, tracing them back to their root forms, understanding each and every word individually, its role in the sentence, why it was inserted, what effect it has on the word(s) before it and the word(s) after it, and thereafter joining that sentence together, piece by piece, like a jigsaw puzzle, after having dissected and fully understood it.
English does have what they refer to as "Sentence Parsing", but this can never be compared with "Tarkeeb" in Arabic. Also, "sentence parsing", as a subject taught formally in schools died out a long time ago. And again, that is besides the fact that Tarkeeb is incomparably more advanced and sophisticated as compared to "Sentence Parsing" in English. Nevertheless, English speakers who had studied sentence parsing should then at least have a vague idea of what Tarkeeb is about.
This Kitaab can also be studied individually; both by those learning Arabic, and those who have already studied Arabic and wish to now study Tarkeeb.